JP2805711B2 - Transmission control device for automatic transmission - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a shift control device for an automatic transmission.

(Prior Art) In an automatic transmission, a normal torque converter and a multi-stage transmission gear mechanism are provided, and the speed of the multi-stage transmission gear mechanism is switched between the operating states of hydraulically operated friction elements such as brakes and clutches. This is done by doing.
Therefore, in each shift speed, the state of the hydraulic pressure applied to each friction element is associated in advance.

By the way, when a certain two frictional elements are temporarily fastened together and the multi-speed transmission gear mechanism causes an internal lock,
This may cause a shift shock. For this reason, JP-A-61-1099
In the gazette of Japanese Patent Publication No. 41, the above-mentioned internal lock is prevented by shifting the hydraulic pressure to the friction element through another hydraulic pressure state different from the hydraulic pressure state at each gear before and after the gear shift. Is disclosed.

Further, recently, in order to prevent a shift shock due to an excessively high engagement speed of a friction element engaged during a gear shift, a hydraulic operation state on the friction element is different from a hydraulic operation state in each shift speed before and after a gear shift. Shifting via another hydraulic operating state is also in practical use.

(Problems to be Solved by the Invention) However, as described above, in the case where the gear shift is performed via another hydraulic operation state different from the hydraulic operation state at each shift speed before and after the shift, the shift shock Although it is advantageous in terms of prevention, there is a problem that the responsiveness of the shift is deteriorated.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a shift control device for an automatic transmission that can satisfy both a shift shock prevention and a shift responsiveness at a high level.

(Structure and operation of the invention) In order to achieve the above object, the present invention has the following structure. That is, a second friction element that includes a hydraulically actuated release operation of a first friction element and a hydraulic actuator that includes an apply chamber and a release chamber, and is fastened only when operating pressure is supplied only to the apply chamber A multi-stage transmission gear mechanism in which a shift is performed by a fastening operation from a state in which operating pressure is supplied to both the apply chamber and the release chamber, and operating pressure is supplied to the first friction element, and the hydraulic pressure is In a shift control device for an automatic transmission configured to perform the shift through a predetermined hydraulic operation state in which operating pressure is supplied only to the release chamber of an actuator, a change rate detecting means for detecting a change rate of an engine load. When the change rate of the engine load detected by the change rate detecting means is equal to or more than a predetermined value, the shift is performed without passing through the predetermined hydraulic action state. And a route prohibition means to be performed.

(Effects of the Invention) As described above, according to the present invention, it is possible to satisfy both the requirements of the shift shock prevention and the shift response in a high level.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows an automatic transmission Z having four forward speeds and one reverse speed.
1 is an engine output shaft, 2 is a torque converter provided with a pump 2a connected to the engine output shaft 1, a stator 2b, and a turbine 2c. The stator 2b reverses the stator 2b from the turbine 2c. It is provided so as to be fixed to the case 4 via a one-way clutch 3 for preventing rotation in the direction. 5 is a turbine 2c of the torque converter 2.
This is a multi-speed transmission gear mechanism connected to a converter output shaft 2d connected to the second gear.

The multi-stage transmission gear mechanism 5 includes a Ravigneaux-type planetary gear mechanism 7 therein. , A long pinion gear 11 meshing with the large diameter sun gear 9 and the short pinion gear 10, and a ring gear 12 meshing with the long pinion gear 11. The small diameter sun gear 8 is
It is connected to the output shaft 2d of the torque converter 2 via a forward clutch 15 disposed on the rear side and a first one-way clutch 16 for preventing reverse driving of the converter output shaft 2d connected in series with the clutch 15. . A coast clutch 17 is connected to a system in which the forward clutch 15 and the first one-way clutch 16 are connected in series.
Are connected and arranged in parallel. The large-diameter sun gear 9 has a 2-4 brake 18 disposed obliquely rearward and a reverse clutch disposed rearward of the 2-4 brake 18.
It is connected to the output shaft 2d of the torque converter 2 via 19. In addition, the long pinion gear 11 has a low & reverse brake 21 for fixing the long pinion gear 11 via a rear carrier 20, and a second permitting rotation of the long pinion gear 11 in the same direction as the engine output shaft 1.
The one-way clutch 22 is connected in parallel, and the front carrier 23 is connected to the output shaft 2d of the torque converter 2 via a 3-4 clutch 24. Further, the ring gear 12 is connected to an output gear 25 disposed in front of the ring gear 12. In the drawing, reference numeral 27 denotes a lock-up clutch that directly connects the engine output shaft 1 and the converter output shaft 2d, and reference numeral 28 denotes an oil pump driven by the engine output shaft 1 via an intermediate shaft 29.

Table 1 shows the operating states of the clutches and brakes at each shift speed in the above configuration.

Hydraulic Circuit Next, a hydraulic circuit for supplying and discharging hydraulic oil to and from each friction element such as the 2-4 brake 18 will be described with reference to FIG.

The hydraulic circuit 60 is first provided with a pressure regulator valve 61 for adjusting the pressure of the hydraulic oil discharged from the oil pump 28 to the main line 100 shown in FIG. 1 to a predetermined line pressure. A throttle valve for generating a throttle pressure according to the throttle valve opening of the engine is provided near the pressure regulator valve 61.
62, a throttle modulator valve 63 for adjusting the throttle pressure, and the pressure / regulator valve described above.
A backup valve 93 for generating a backup pressure for increasing the line pressure generated at 61 when the S and L ranges are selected is provided.

The hydraulic circuit 60 also has a manual valve 64 that selectively sends the line pressure generated by the pressure / regulator valve 61 to each hydraulic line according to the selected range, and a line pressure that operates according to the shift speed. , 2-3, and 3-4 for selectively supplying the frictional elements to the friction elements.

The manual valve 64 has an input port f into which line pressure is introduced from the main line 100, and first to fifth output ports a to e. Thus, the first, second, and third output ports a, b, and c are connected to the fifth output port e in the R range. The first to fifth output lines 101 to 1 are connected to the output ports a to e, respectively.
05 is connected.

Also, the above-mentioned 1-2, 2-3, and 3-4 shift valves 71,
Numerals 72 and 73 each have a configuration in which spools 71a, 72 and 73a are biased to the right in the drawing by springs, and control ports 71b, 72b and 73b are provided on the right side of these spools.
The first control line 106 branched from the main line 100 is connected to the control port 71b of the 1-2 shift valve 71.
Is the control port 72 of the 2-3, 3-4 shift valve 72, 73
b and 73b are the second, branched from the first output line 101,
The third control lines 107, 108 are respectively connected, and the control lines 106, 107, 108 are provided with first, second, and third solenoid valves 76, 77, 78, respectively. When these solenoid valves 76 to 78 are turned off, the control pressure is introduced into the control ports 71B to 73b of the shift valves to position the spools 71a to 73a on the left side in the drawing. The control pressure in the ports 71b to 73b is drained to position the spools 71a to 73a on the right side.

Here, these solenoid valves 76 to 78 are controlled to be turned on and off in accordance with the gear to be set according to the vehicle speed of the vehicle and the throttle valve opening of the engine. The combination pattern of ON and OFF of each of the solenoid valves 76 to 78 at each shift speed is set as shown in the above table.

On the other hand, among the first to fifth output lines 101 to 105 connected to the respective output ports a to e in the manual valve 64, the first output which is communicated with the main line 100 in each of the forward ranges D, S, and L. Line 101 is a one-way orifice 8
It is guided to the forward clutch 15 via 0. Therefore, the forward clutch 15 is always engaged in the D, S, and L ranges. The first output line 10
1 is provided with an ND accumulator 81 for buffering when the forward clutch is engaged.

A line 111 is branched from the first output line 101 and led to the 1-2 shift valve 71. The branch line 111 is connected to the first solenoid valve 7.
When 6 turns ON and the spool 71a moves to the right,
Hydraulic apply chamber for servo mechanism 35 (described later) of 4 brake 18
It is communicated with the servo apply line 150 reaching 35b. Therefore, when the first solenoid valve 76 is ON in the D, S, and L ranges, that is, in the D range, the second, third, and fourth speeds, and in the S range,
At the third speed and the second speed in the L range, a servo apply pressure is introduced into the apply chamber 35b.

Next, the internal configuration of the servo mechanism 35 for operating the 2-4 brake 18 (friction element) will be described. This servo mechanism
Reference numeral 35 denotes a piston 35a associated with the 2-4 brake 18, a hydraulic apply chamber 35b serving as a fastening-side oil chamber and a hydraulic release chamber 35c serving as a release-side oil chamber partitioned by the piston 35a on the left and right in the drawing. A spring 35d compressed in the hydraulic release chamber 35c to urge the piston 35a toward the apply chamber 35b
And The piston 35a is formed such that its pressure receiving area is larger in the release chamber 35c and smaller in the apply chamber 35b. Due to the difference in the pressure receiving areas, the fastening pressure (line pressure) of the apply chamber 35b is reduced. Regardless of the operation or non-operation, when the release pressure (line pressure) is applied to the release chamber 35b, the piston 35a is moved leftward in the drawing by the release pressure, and the 2-4 brake 18 is operated to the open side. The configuration is such that On the other hand, when the 2-4 brake 18 is requested to be engaged, the engagement pressure is introduced into the apply chamber 35b and the release chamber 3
By discharging the release pressure of 5c, the piston 35a is moved to the right in the drawing, and the 2-4 brake 18 is engaged.

In addition, a one-way orifice 3 is provided in a line 150 serving as a fastening passage communicating with the apply chamber 35b of the servo mechanism 35.
6 are provided. The one-way orifice 36 includes a throttle portion 36b having an opening 36a having an area smaller than the opening area of the line 150, and a spring 36c for urging the throttle portion 36b downstream (toward the servo mechanism 35). ing. Therefore, the one-way orifice 36 exerts a throttling effect on the supply of oil to the apply chamber 35b of the servo mechanism 35, and when the oil in the apply chamber 35b is discharged, the spring 36c usually contracts due to the oil pressure to restrict the supply. Since the portion 36a is unseated, the throttling effect is lost. The spring 36c has a relatively strong urging force, and when the engine is decelerated, the line pressure (the fastening pressure supplied to the servo mechanism 35) also decreases as the throttle valve opening decreases. Is smaller than the value corresponding to the set throttle valve opening value of the low opening, the urging force is set to the urging force value that overcomes the fastening pressure and seats the throttle portion 36a, and the fastening force is set by this configuration. When the pressure is equal to or less than the value, the fastening pressure is exhausted while the line 150 is narrowed.

A piston-side accumulator 83 that suppresses a sudden increase in the fastening pressure of the servo mechanism 35 to the apply chamber 35b is disposed in the line 150b downstream of the one-way orifice 36. The accumulator 83 includes a piston 83a, an oil chamber 83b in which oil in the line 150 flows to move the piston 83a to the left in the drawing, and a spring 83c compressed in the oil chamber 83b. , The line pressure acts as a back pressure via the line 151. The biasing force of the spring 83c is set to a large value, and the line
By moving the piston 83a from the stage where the hydraulic pressure of 150 is a small value, the piston 35a of the servo mechanism 35 is gradually moved, and the 2-4 brake 18 is slowly engaged.

Also, in FIG. 2, the main line is set in the D and S ranges.
The second output line 102 communicating with 100 is led to a 2-3 shift valve 72. When the second solenoid valve 77 is OFF and the spool 72a is located on the left side, the line 102 is connected to the 3-4 clutch line 1 which reaches the actuator 43a of the 3-4 clutch 43 via the one-way orifice 84.
Communicated with 13. Therefore, when the second solenoid valve 77 is OFF in the D and S ranges, that is, the 3-4 clutch 24 is engaged at the third and fourth speeds of the D range and the third speed of the S range. In the 3-4 clutch line 113, a bypass valve 85 and a 2-3 timing valve 86 are provided in parallel with the one-way orifice 84 so as to adjust the engagement timing of the 3-4 clutch 24. , Said 3
The -4 clutch line 113 is also provided with a 2-3 accumulator 87 for buffering when the 3-4 clutch is engaged.

Further, the line 1 branched from the 3-4 clutch 113
14 and a line 115 branched from the first output line 101
Are guided to the 3-4 shift valve 73. When the third solenoid valve 78 is OFF and the spool 73a is located on the left side, the line 114 branched from the 3-4 clutch line 113 is connected to the servo mechanism 3 via the one-way orifice 88.
In the servo release line 116 which leads to the release room 35c of 5,
Also, a line 115 branched from the first output line 101 is connected to a coast clutch line 117 which reaches the coast clutch 17 via a one-way orifice 89.
Therefore, in the D and S ranges, the second and third solenoid valves 7
When both 7 and 78 are OFF, that is, at the 3rd speed of the D range and the 3rd speed of the S range, the servo release pressure is introduced into the release chamber 35c of the servo mechanism 35, and the 2-4 brake 18 is released. 3rd solenoid valve 78 is OFF in S, L, range
In other words, the 3rd speed in the D range, the 3rd speed in the S range, and the 2nd speed in the L range, the 2nd speed and 3rd speed when the hold switch in the S range is operated, and the 1st speed and 2nd speed when the hold switch in the L range is operated. Coast clutch 17 in speed
Will be concluded.

Here, the 3-4 clutch line 113 and the line 1
A 3-2 timing valve 90 for adjusting the discharge timing of the 3-4 clutch pressure and the servo release pressure via the respective branch lines 118 and 119 is provided between the line 114 branched from the line 13 and the line 114. A city valve 91 is provided. The coast clutch line 117 is provided with a bypass line 120 that bypasses the one-way orifice 89, and opens and shuts off the line 120.
A capacity valve 92 is provided. This valve 92
The bypass line 120 is connected when the 3-4 clutch pressure is generated, and when the manual valve 64 is selected to the S range or the L range and the third output line 103 is connected to the main line 100. It is opened to adjust the coast clutch pressure discharge timing.

The fourth output line 104 communicated with the main line 100 in the L range by the manual valve 64 is led to the 1-2 shift valve 71 via the low reduction valve 94 and the line 122. When the first solenoid valve 76 is OFF and the spool 71a is located on the left side, the line 122 is connected to the one-way orifice 95 and the shuttle valve 96.
Through the low & reverse brake line 123 leading to the low & reverse brake 21. Therefore, when the first solenoid valve 76 is OFF in the L range, that is, at the first speed in the L range, the low & reverse brake 21 is engaged.

Further, a fifth output line 105 communicating with the main line 100 in the R range communicates with the low & reverse brake line 123 via the one-way orifice 97 and the shuttle valve 96, and a one-way output from the fifth output line 105. A reverse clutch line 124 that reaches the reverse clutch 19 via the orifice 98 is branched. Therefore, in the R range, the low & reverse brake 21 and the reverse clutch 19 are always engaged. The reverse clutch line 124 is also provided with an NR accumulator valve 99 for buffering when the reverse clutch is engaged. Further, a line 125 branched from the fifth output line 105 is led to the pressure increasing side of the regulator valve 61 so as to increase the line pressure in the R range.

In addition, in addition to the above configuration, the hydraulic circuit 60 includes a lock-up clutch 26 in the torque converter 2 shown in FIG.
Is provided with a lock-up valve 201 for activating the switch. A torque converter line 202 is led from the pressure / regulator valve 61 to the valve 201, and is connected as a control line 203 at one end. When the lock-up solenoid valve 204 provided on the control line 203 is turned on, the control pressure in the control port 201b is drained, and the spool 201a is located on the right side.
2 communicates with a line 205 leading into the torque converter 2,
As a result, the internal pressure of the torque converter 2 increases, and the lock-up clutch 27 is engaged. When the solenoid valve 204 is turned off and the control pressure is introduced into the control port 201b to move the spool 201a to the left, the torque converter line 202 communicates with the lock-up release line 206 and the torque converter 2 The lock-up clutch 27 is released by introducing a lock-up release pressure therein.

Table 2 shows the first, second, and third speeds, and 3-4
Clutch 24, 2-4 brake 35, first to third solenoids
The relationship between the operating states of 76 to 78 is shown together. In Table 2, what is shown as the intermediate position is the "other hydraulic operation state", which will be described later.

Shift Control When shifting between the first gear, the second gear, and the third gear, the operation state of the first to third solenoids 76 to 78 is switched in a manner as shown in Table 2 below. However, the shift from the third speed to the second speed is usually performed via the state of the intermediate position shown in Table 2 from the viewpoint of shift shock prevention. It is directly switched to the second speed operating state.

The meaning of passing through the intermediate position will be described as follows.

First, in shifting from the third speed to the second speed, the 3-4 clutch 24 is released and the 2-4 brake 35 is engaged. At this time, the engagement of the 2-4 brake 35, that is, the displacement of the piston 35a to the right side in FIG. 2 is rapidly performed, so that a large shift shock occurs. To explain this point in detail, in the third gear state before shifting, hydraulic pressure is supplied to both the apply chamber 35b and the release chamber 35c of the 2-4 brake 35, and the difference between the pressure receiving area of the piston 35a and the return spring 35d. By the urging force, the piston 35a is moved to a position on the left side of FIG.
The four brakes 35 are released. On the other hand, at the second speed, the hydraulic pressure in the release chamber 35c is released, but at this time, the hydraulic pressure is still supplied to the apply chamber 35b. As a result, the piston 35a is suddenly displaced to the right in FIG. 2, and the 2-4 brake 35 is rapidly engaged, causing a shift shock. FIG. 3 shows a hydraulic pressure change state when the third speed is switched to the second speed without passing through the state of the intermediate position.

At the time of shifting from the third speed to the second speed, when passing through the state of the intermediate position, the following is performed. First, the solenoid
By setting 76 to 78 at the intermediate position, the hydraulic pressure in the apply chamber 35b is released, and the piston 35a returns to the position on the left side in FIG. Thereafter, when the solenoids 76 to 78 are switched to the second speed, hydraulic pressure is again supplied to the apply chamber 35b,
At the same time, the hydraulic pressures in the release chamber 35c and the 3-4 clutch 24 are released. The hydraulic pressure supplied to the apply chamber 35b at this time is low due to the action of the accumulator 83, and the 2-4 brake is slowly applied, thereby preventing a shift shock.

As can be understood from the above description and the comparison between FIGS. 3 and 4, a time delay is caused in shifting from the third speed to the second speed as compared with the case where passing through the intermediate position is not performed. Will come. Therefore, in the present invention, the second to third gears
At the time of shifting to high speed, while normally preventing a shift shock via the intermediate position, at the time of an acceleration request in which the rate of change in engine load, for example, the accelerator pedal depression speed becomes large,
A quick shift is obtained without passing through the intermediate position.

In FIG. 6, U is a control unit constituted by using a microcomputer, and the first to third solenoids 76 to 78 are controlled by the control unit U. A throttle opening signal from the sensor 310 and an accelerator opening signal from the sensor 321 are input to the control unit U. In addition, a vehicle speed signal or the like is input to the control unit U for a shift determination or the like, but points not directly related to the present invention are not shown.

The flowchart of FIG.
The shift control from the second speed to the second speed is shown, and the flowchart will be described below. In the following description, P indicates a step.

First, at P1, it is determined whether or not the throttle opening is equal to or greater than a predetermined value. If the determination of P1 is YES, P
In 2, it is determined whether or not the accelerator depression speed is equal to or higher than a predetermined value. The accelerator pedal speed is
It is calculated by differentiating the accelerator opening. This P2
If the determination is NO, in P3, all of the first to third solenoids are turned off to return to the intermediate position. After this P
In 4, it is determined whether or not a predetermined time (a few seconds) has elapsed since the intermediate position. If the result of this P4 is NO
Returning to P3, the state of the intermediate position is maintained. If the determination in P4 is YES, in P5, all of the first to third solenoids 76 to 78 are turned on (second speed operating state) and the process ends.

When the determination in P1 is NO, or when the determination in P2 is YES, the vehicle does not pass through P3 and P4. Go to P5.

As described above, in the present embodiment, when the throttle opening is small, it is determined that the shift shock is not a problem, and the intermediate position is not passed through at this time.

In the above-described embodiment, the case where the hydraulic operation state at one of the gear stages before and after the shift is changed as the other hydraulic operation state has been described. The same applies to those that pass through.

[Brief description of the drawings]

FIG. 1 is a skeleton diagram showing an example of a transmission mechanism. FIG. 2 is a diagram showing an example of a hydraulic circuit. FIG. 3 is a diagram showing a change in hydraulic pressure when the vehicle does not pass through another hydraulic operation state. FIG. 4 is a diagram showing a change in hydraulic pressure under another hydraulic operation state. FIG. 5 is a flowchart showing a control example of the present invention. FIG. 6 is a diagram showing a control system of a shift solenoid. U: Control unit 5: Multi-speed transmission gear mechanism 24: 3-4 clutch 35: 2-4 brake 35a: Piston 35b: Apply chamber 35c: Release chamber 76-78: Shift solenoid 310: Sensor (throttle opening) 320: Sensor (accelerator opening)

Claims (1)

(57) [Claims] 1. A hydraulically actuated first friction element releasing operation and a second actuator which is provided with a hydraulic actuator comprising an apply chamber and a release chamber, and is fastened only when the operating pressure is supplied only to the apply chamber. A multi-stage transmission gear mechanism in which a shift is performed by a fastening operation from a state in which operating pressure is supplied to both the apply chamber and the release chamber of the friction element, and operating pressure is supplied to the first friction element; And a shift control device for an automatic transmission configured to perform the shift through a predetermined hydraulic operation state in which operating pressure is supplied only to the release chamber of the hydraulic actuator. Rate detecting means, and when the change rate of the engine load detected by the change rate detecting means is equal to or more than a predetermined value, the speed change without passing through the predetermined hydraulic action state. Shift control device for an automatic transmission, characterized by comprising a through inhibiting means for causing.